<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>链接</title>
    <style>
        *{margin: 0;padding: 0;list-style-type: none;}
        a{
            text-decoration: none;
        }
        .clearfix:after{
            content:'';
            diaplay:block;
            clear:both;
        }
        .wrap{
            height: 50px;
            width: 300px;
            margin: 20px auto 0;
            border: 1px solid transparent;
            border-bottom: 1px solid #ccc;
        }
        ul li{
            float: left;
            width: 100px;
            height: 50px;
            text-align: center;
            font-size: 20px;
            box-sizing: border-box;
            border: 20px auto 0;
            /* background-color: skyblue; */
        }
        ul li:nth-child(1):hover{
            background-color: #ccc;
            border: 1px solid orange;
            border-bottom: 1px solid #ccc;
        }
        ul li:nth-child(2):hover{
            background-color: #ccc;
            border: 1px solid orange;
            border-bottom: 1px solid #ccc;
        }
        ul li:nth-child(3):hover{
            background-color: #ccc;
            border: 1px solid orange;
            border-bottom: 1px solid #ccc;
        }
        .clear{
            width: 0px;
            height: 0px;
            /* border: 1px solid red; */
            clear: both;
            /* background-color: blue; */
        }
    </style>
</head>
<body>
    <div class="wrap">
        <ul>
            <li><a href="">链接1</a></li>
            <li><a href="">链接2</a></li>
            <li><a href="">链接3</a></li>
            <li class="clear"></li>
        </ul>
    </div>
</body>
</html>